Electronic book



FIG. 1 is a front view of an electronic book showing the claimed design;

FIG. 2 is a rear view thereof;

FIG. 3 is a rear perspective view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for an electronic book, as shown and described. 